DTC P1432: Fuel Tank Pressure Sensor Signal Low: Description

WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The CNG Fuel Tank Pressure (FTP) sensor is a pressure transducer. The Fuel Injector Control Module (FICM) supplies about 5 volts on the FTP sensor reference voltage circuit. The FICM also supplies a signal circuit and a low reference circuit to the FTP sensor. When fuel level/tank pressure is full the FTP signal voltage rises to 4.1 volts. As fuel level/tank pressure decreases to empty, the FTP signal voltage drops to around 0.5 volts. The FICM communicates the FTP data to the Powertrain Control Module (PCM) by a Pulse Width Modulated (PWM) circuit. The PCM uses the FTP sensor and the Fuel Tank Temperature (FTT) sensor in order to determine the amount of fuel within the fuel tank. This DTC sets when the FTP sensor signal voltage is below the normal operating range of the sensor.